2007 Ford F-150 4.6L Engine Misfire: P0307, P0316, P1000 Codes After Multiple Coil Pack Replacements
Hi, I own a 2007 Ford F-150 with a 4.6L V8 engine and approximately 89,000 miles on the odometer. About a few months ago, I started receiving misfire codes, specifically P0307 and P0316, indicating misfires on cylinders 2 and 4 (P0307) and a starting issue with initial engine cranking (P0316). Later, the problem shifted to cylinders 4 and 7, triggering another P0307 code. I replaced all eight spark plugs and one coil pack initially, followed by two additional coil packs over the next week. This week, after installing eight new coil packs, the engine started running rough again, and the same codes—P0307, P0316, and P1000—are now appearing. The vehicle has been cleared of codes using a scan tool, but within 24 hours, the misfire returns. I’ve already replaced the mass air sensor (MAS) and confirmed that cylinder 7’s injector is functioning—however, I’m still unsure what to do next. Could it be a fuel delivery issue? A faulty injector? Or could low compression or internal engine wear be contributing? Any advice on diagnosing this persistent misfire with these specific OBD2 codes would be greatly appreciated. Thank you, FB
For P0307, start with a fuel pressure test and monitor the drop during operation using a scan tool. This will help determine if an injector is leaking. Also check spark plug condition—look for dry, wet, or black/tan deposits. P1000 typically occurs when codes are cleared without proper reset or after disconnecting the battery; ensure you're not resetting the system incorrectly. A fuel system cleaner like SeaFoam or Techron may help clean carbon buildup. Note: Avoid cheap spark plug replacements—they can sometimes cause intermittent misfires or poor performance.